Rob Ryan speaks about Jay Ratliff

IRVING, Texas -- One of the Cowboys more dependable players, nose tackle Jay Ratliff, is lost for the season after undergoing sports hernia surgery on Thursday.

Ratliff missed seven games prior to the surgery because of ankle and groin problems.

"I’m sure he’s been extremely frustrated," defensive coordinator Rob Ryan said. "I know he’s done everything he can to try to help us. I know he hasn’t had a career of injuries – he’s always played. It’s got to be frustrating for him like a lot of his teammates, you know Sean Lee and (Barry) Church and those guys and Kenyon Coleman."

The Cowboys have 11 players on injured reserve and eight of them are defensive players. Safety Matt Johnson is on the reserve/injured returnable list and nose tackle Josh Brent is on reserve/non-football injury illness list.

Ryan has mixed his lineups due to the injuries. He's on his third nose tackle of the season, Sean Lissemore, Brent and Ratliff have played it, he's lost his slot cornerback, Orlando Scandrick, and two starting defensive linemen, Kenyon Coleman and Ratliff and two starting inside linebackers in Bruce Carter and Lee.

"It’s got to be tough. I think players are happiest when they’re playing," Ryan said. "We’re going to miss Jay, but that can’t be the reason why they’re not successful. We have to keep fighting and keep playing. We’ve got good players in those spots. Sean played pretty well considering he only had four snaps as a nose tackle up until then. He did a good job, and Rob Callaway did a nice job staying square when he wasn’t jumping offside. We’re going to be fine. It’s a tough game. They’ve got an All-Pro game. But at this time of the year, it’s who’s going to play better and who wants it more."